The present invention relates to support arms and more specifically to multi-position adjustable support arms for supporting electronic devices such as flat panel electronic display screens or the like.
Most work stations, lap tops, etc., include some type of display screen for displaying information for viewing. Early workstations included relatively bulky cathode ray tube (CRT) type displays that typically had box type forms to accommodate a tube required to create display images. While CRTs were useful for displaying information, such displays had several shortcomings. First, because of their large size, CRTs required a large amount of worktop space. CRT space requirements are especially problematic in relatively small partitioned personal spaces where workstation users often have a minimal amount of worktop space.
Second, CRTs are not ergonomically friendly. To this end, it has been known for a long time in the furniture industry that people are most comfortable when supporting furniture can be at least somewhat customized to fit specific body characteristics. For instance, most office chairs now include height adjustable seat mechanisms that, as the label implies, allow seat height to be raised and lowered by a user so that an optimal height for supporting a specific user can be configured. As another instance, many office chairs include height adjustable arm supports that, like the adjustable seats, facilitate raising and lowering of arm supports to optimally support different chair users.
In addition, it has been known for a long time in the furniture industry that, even where only one person uses a piece of furniture, comfort over extended periods can be increased appreciably if the furniture is adjustable to support the user in several different positions. To this end, anyone that has had to sit in an airline seat during an extended flight knows first hand that, while the seat may initially seem comfortable, by the end of a several hour flight, despite ability to change position to a limited degree, stiffness and even pain often result.
In the case of a display screen, to accommodate physical differences between users (e.g., at a receptionist desk, at a ticket counter, etc.) and indeed the same user over an extended period, a display screen should be moveable in many different ways so that the relative position of a screen surface to a user's eyes is optimally adjustable. In this regard, optimally, display screen position should be changeable vertically (i.e., up and down), laterally (i.e., left and right) about a vertical axis (i.e., so that a vertical lateral edge can be moved forward or rearward while the opposite lateral edge moves rearward and forward, respectively)), about a first horizontal axis parallel to the display screen surface (i.e., so that the top edge of the screen surface can tip forward or rearward while the lower edge tips rearward or forward, respectively), along a depth dimension (i.e., the screen can be moved forward or rearward) and about a second horizontal axis perpendicular to the display screen surface (i.e., so that a first edge of the display screen that is initially a top horizontal edge can be rotated into a vertical lateral edge orientation—i.e., enabling either landscape or portrait viewing).
In the case of CRTs, the size and related weight of a typical CRT has made it difficult to cost effectively support a CRT for optimal movement. For instance, while some CRTs are supported for rotation about a vertical axis and/or tipping about a horizontal axis, in most cases CRTs are not supported to enable the full compliment of optimal adjustability. Where CRTs are supported to facilitate a subset of optimal movement, there is no known support structure that facilitates the full compliment of movement (e.g., no support structure facilitates rotation about the second horizontal axis perpendicular to the display surface). In addition, where CRTs are supported to facilitate a subset of optimal movement, the structure required is usually relatively bulky, complex, expensive to configure and, in many cases, is not believed to work very well.
With respect to functionality, a CRT support structure works well if the structure allows smooth and minimal effort transitions of the CRT between different positions and if the CRT remains in a set position after the CRT is released. Hereinafter the phrase “position maintenance” will be used to refer to the notion of a display screen remaining in a set position after release (i.e., position performance is a measure of how well a screen remains in a set position after release). In the case of known CRT support structure, it is believed that the structure may not operate smoothly, with minimal effort and/or may not exhibit acceptable position maintenance.
Third, known support structure for CRTs often is configured to support a single CRT type having known dimensions and weight and therefore cannot be used with other CRT types. In fact, in many cases adjustable support structure is built right into a CRT base and cannot be used to support another CRT when, for instance, a user decides to upgrade to a new CRT including a larger or more vivid screen.
Fourth, where support assemblies have been configured that can be used with CRTs having different dimensions and weights, the structure required to secure a CRT to the support assembly has usually required many components and the mounting task has typically included many steps and required excessive time to accomplish. Here, because of the cost associated with such structures, often office administrators opt to forego the advantages associated with such systems and, because of the costs (i.e., time, hassle) associated with upgrading to better displays, administrators opt to forego advantages associated with display upgrades.
Fifth, even where a CRT is supported by a structure that enables many relative display positions, such structures usually do not allow the CRT to be effectively removed from the space above a work surface so that essentially the entire work surface is useable for other purposes. For instance, in the case of a partitioned personal space, the rear edges of work surfaces are typically up against partition walls so that the CRT position is always somewhere above and obstructing the work surface.
In the last few years new technologies have evolved that have enabled configuration of flat or thin panel type monitors. For instance, liquid crystal displays (LCDs) and plasma displays have been developed that have relatively narrow depth dimensions (e.g., on the order to 1 to 2 inches). Hereinafter, the phrase “flat panel display” will be used generally to refer to any type of flat or thin panel including but not limited to LCDs, plasma displays, etc. In addition to being thinner along the depth dimension, flat panel displays are typically lighter weight that CRTs having the same viewing screen size.
Support arm structure for flat panels has been developed that overcomes many of the problems described above with respect to CRT support structure. For instance, arm structure has been developed for supporting flat panel displays so that the displays can be moved into any of the optimal orientations. In addition, support structure has been developed that allows flat panel display screens to be moved essentially up against wall structure adjacent a work surface so that the screens are out of the way of a work surface user. Moreover, support structure has been developed that allows a user to quickly release a flat panel display for removal or replacement and for supporting universal type mounting of different types of flat panel display screens. Furthermore, support structure has been developed that can be adjusted to counterbalance different weights of various flat panel displays that may be used with the support structure.
While the new support arm structures for flat panel displays overcome many of the problems associated with CRT type support structures, even these new structures have several shortcomings. First, in many cases it is believed that these new structures will not operate in a smooth fashion with minimal effort and may not exhibit good position maintenance. For instance, in many cases first and second components linked to enable rotation of a flat panel display screen about a horizontal axis that is parallel to the display screen surface will be linked by a pin or bushing where frictional force between the two components is relied upon to maintain a set position. Here, where the frictional force is sufficient to maintain a set position (i.e., to facilitate good position maintenance), when the position is to be altered, often a large force has to be applied to start the movement such that the screen position will shoot past an intended or target position and another adjustment is required to compensate for the overshoot. Thus, in these cases movement is not smooth, effort to change positions is not minimal and, in some cases, position maintenance is not good or may deteriorate over time (e.g., during repeated use, pin/bushing friction may decrease).
Second, some flat panel support assemblies include components that, while enabling a full compliment of optimal screen movements, require multiple machinations to change screen position. For instance, to facilitate smooth and minimal effort movement and position maintenance, some assemblies include components that can be tightened and loosened to maintain relative positions and to allow position changes. For instance, in the case of first and second components linked to facilitate rotation of a screen about a horizontal axis parallel to a display screen surface, a tightening screw or the like may be provided to adjust the friction between the first and second components, the screw tightened to increase friction and maintain relative positions and loosened to decrease friction and allow position changes.
Here, to change screen position about the horizontal axis, a user has to loosen the tightening screw, adjust screen position and then tighten the screw again. During this process, the user will typically need to access the space behind the screen to loosen and tighten the screw and therefore will not be in a normal screen using position (i.e., in front of the screen). Thus, after adjustment and when the user is positioned in the normal using position, the user may find that the new position is not optimal and may have to re-perform the adjusting process (i.e., loosening, movement and tightening). While this process may not appear burdensome at first blush, when the process is repeated several times a day which is necessary to constantly have the display in an optimal position, the machinations required to change position become extremely burdensome. Moreover, where a support structure includes several tightening screws or other friction adjusting components for increasing position maintenance forces, the task of optimally adjusting position is exacerbated.
Third, while at least some flat panel display support assemblies include mechanical configurations that enable quick release of the display from the support assembly for attachment/removal and/or replacement, known mechanical configurations are relatively clumsy to use. For instance, known configurations may require a user to unscrew one or several small screws that are located in the space to the rear of the display screen prior to removal of the display from the support assembly. In other known cases two separate leaf springs have to be simultaneously pressed to unlock a display screen from a support assembly where the leaf springs are arranged in a non-ergonomic position with respect to the display. For instance, in some cases the ends of two leaf springs extend upward and therefore require a user to reach over a top edge of a display screen which makes it awkward to support the display while compressing the leaf springs to decouple the display from the support.
Fourth, in known cases where support assemblies allow adjustment of a counterbalancing force so that a single assembly can accommodate display screens having different weights, the adjusting interfaces typically are difficult to access and/or require special tools (i.e., a screw driver, a wrench, etc.).
Fifth, in the case of known flat panel support assemblies, there is no “secondary movement” that occurs when one component is moved with respect to another that aids in optimal display screen placement. In this regard, the phrase “secondary movement” is used to refer to mechanical movement that occurs as a result of some other movement caused by an assembly user. For instance, when a display screen is to be tipped so that a top horizontal edge and a bottom horizontal edge tip forward and rearward, respectively, assuming a user's eye's remain at a constant height and that the user will want to maintain a line of sight perpendicular to the display screen surface, an automatic secondary movement may cause the display screen to move slightly upward so that the screen rotates generally about the user's eye level. Similarly, when a display screen is to be tipped so that a top horizontal edge and a bottom horizontal edge tip rearward and forward, respectively, assuming a user's eye's remain at a constant height and that the user will want to maintain a line of sight perpendicular to the display screen surface, an automatic secondary movement may cause the display screen to move slightly downward so that the screen rotates generally about the user's eye level. Known support arms do not automatically facilitate secondary movements.
Sixth, known flat panel display support assemblies often have designs that are not versatile so that the assemblies can only be used in one fashion. For instance, at least some support assemblies include lower and upper support arm subassemblies and a pan tilt subassembly where the lower assembly includes a four bar linkage that facilitates height adjustment generally, the upper arm subassembly is simply an extension member that does not facilitate height adjustment, the pan tilt subassembly is mounted to the upper arm subassembly, the upper arm subassembly is mounted to the lower arm subassembly and each configuration requires each of the upper, lower and pan tilt subassemblies. Here, for instance, the pan tilt subassembly cannot be mounted directly to the lower arm subassembly and the pan tilt and upper arm subassemblies cannot be used without the lower arm subassembly to provide different configurations that may be desirable under certain circumstances.
Seventh, in order to provide an arm assembly that has a quality feel during operation, components have to fit together with minimal slop. For instance, where a first arm member includes a post received in a cylindrical cavity formed by a second arm member to facilitate relative movement of the first and second arm members about a common axis, the external surface of the post has to precisely mirror the internal surface of the cavity to facilitate a quality feel during rotation. Here, precise machining requirements appreciably increase arm component cost.
Eighth, where arm assemblies include a counterbalancing spring mechanism, typically the spring mechanism is juxtaposed between other arm assembly components which makes it difficult at best to access the spring mechanism. Here, spring mechanism access may be desirable for maintenance purposes or, in at least some cases, so that springs having different characteristics can be installed (e.g., spring characteristics may be different depending on weight of the screen supported thereby).
Thus, it would be advantageous to have a flat panel display support assembly that operates smoothly and with minimal effort and that exhibits good position maintenance. In addition, it would be advantageous to have a support structure of the above kind that allows quick and ergonomically optimal release of a flat panel display screen from the structure and that could be used in any of several different advantageous configurations. Moreover, it would be advantageous to have a support structure of the above kind that causes optimal secondary movement in at least some cases and that is designed to be easily maintained and relatively inexpensive to manufacture.